<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>买机票</title>
</head>
<body>
<script>
    var paobu = prompt("请输入当前月份");
    if (paobu>=5 && paobu<=10){
        var sex = prompt("头等舱还是经济舱");
        if (sex == "头等舱"){
            alert("2000元")
        }else if (sex == "经济舱"){
            alert("800元")
        }
    }else{
        var que = prompt("头等舱还是经济舱");
        if (que == "头等舱"){
            alert("800元")
        }else if (que == "经济舱"){
            alert("200元")
        }
    }
</script>
</body>
</html>